Piette



(No Model.) 2 Sheets-Sheet 1.

L. PIETTE 82; P. K'RIZIK.

ELECTRIC ARC LAMP.

No. 273,888. Patented Mar. 13.1883.

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N4 PETERS. Phot l V Y I "annual/(III ZF 5/0 qrwew WM, M

(No Model.) 2 Sheets-Sheet 2.

L. PIETTE 8: F. KRIZIK.

ELECTRIC ARC LAMP.

No. 273,888. Patented Mar. 13,1883.

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jia 72 2 1 1 N. PETERS PmvLicho n mr. Waifington, 0.6.

UN TED STATES PATENT OFFICE.

IiUDWlG PIETTE AND FRANZ KRIZIK, OF PILSEN, AUSTRIA-HUNGARY.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 273,888, dated March 13, 1883.

Application filed June 15), 1882.

(No model.) Patentedin England April 6, 1380; in Germany April 7, 1880; in Austria Hungary April 16, 1880; in France June 8, 1880, and in Belgium June 11, 1880.

T 0 all whom it may concern Be it known that we, LUDWIG- PIEr'rE and FRANZ KRIZIK, subjects of the Emperor of Austria, and residents of Pilsen, in the Empire of Austria, have invented a certain Improvement in Electric Lamps, of which the following is a specification.

This invention relates to a method of efilectingautomatically the regulation of the distance of the carbons in an electric lamp, without the aidot' clock-work or other like mechanism, by the use of solenoids having special cores, such solenoids and cores being applicable where, as in electriclamps, uniformity of attractive force has to be maintained throughout a considerable length of stroke. In an electric lamp according to this invention there are two solenoid coils placed end to end, with their axes in the same straight line, and with one iron core free to slide lengthwise within both, this core carryingatits end one of the carbons of the lamp and being balanced when it is vertical or running on rollers when it is horizontal. The one solenoid coil,of low resistance, is in the lampcircuit. The other, of high resistance, is in a branch circuit connecting the conductors to and from the lamp. The core is so shaped that so long as the two solenoids exert equal attractive forces it remains stationary, notwithstanding that it mayhave been previously moved lengthwise so as to extend farther into or through the one coil than the other; and in order that it may have this property it is made with the mass of its metalreduced toward the ends. This may be done either by taperingit from the middle of its length to a less diameter at each end, or by boring it from each end with a tapering here; or, instead of giving the metal a regular taper externally or internally, its diameter or thickness may be reduced by steps from the middle each way; or it may be made of a number of pieces of iron rod or tube united end to end, with pieces of nonmagnetic material of different lengths intervening between the lengths of iron. The core so constructed carrying one of the carbons, will then adjust itself, moving the one carbon to or from the other, until the attractive forces exerted on the core by the two solenoids in opposite directions become balanced. When the *arbons are too near the resistance of the arc is so far lessened that the solenoid in the circuit of the carbons becomes the more powerful of the two,and the core thereupon moves so as to sepa ate the carbons. When, on the other hand, the carbons are too far apart the resistance of the are is so much augmented that the solenoid in the circuit of the carbons becomes the weaker, and the core thereupon moves so as to bring the carbons nearer together. Itis of advantage to combine with the lamp an automatic shunt of any known construction, so

that when the lam p is extinguished the current is shunted into the general circuit.

In the drawings, Figures 1, 2, 3, and 4 are diagrams illustrating the principles on which this invention is founded. it an iron core of uniform section, as shown in Fig. 1, be placed within two solenoid coils, S and S, of equal magnetic force, the attraction on the core will depend on its position relatively to the coils. It is strongest when one end of the core is in the middle of the coil and weakest when the middle of the core is in the middle of the coil. Hence, when the core is in the position shown in Fig.1 it will he more strongly attracted by S than by S. When, however, the mass of the core at difi'erent parts of its length varies the attraction of the two coils upon it may be equalized. Thus by making the core in the form of a double cone, as shown in Figs. 2, 3, and 4, notwithstanding the different positions occupied by the core, it remains equally at tracted by the two coils S S, Figs. 2 and at showing its extreme positions each way and Fig. 3 its middle position. The core, instead of being truly tapered toward each end, may be reduced by steps, as indicated in Fig. 5; or it maybe hollowed out bytapering holes, as in Fig. or it may be made up of a number of separate lengths of iron connected together by nonmagnetic materiahas indicated in Fig.

7, and these lengths may be bored through with holes of diti'erent diameter, as indicated in Fig. 8. By thus constructing the cores they may be made to move over considerable distances without undergoing change of attraction, and they are therefore suitable for regulating the distance of the carbons in electric lamps.

ICO

Figs. 9, 10, and 11 show various constructions of lamps in which they are so applied. In Fig. 9 the double-coned core F is attached to the socket of the upper carbon, the whole being balanced by a weight, g, attached to a cord passing over a pulley, R, and free to move within the two solenoid coils S and S. The coil S, of large wire, presenting small resistance, is in the circuit of the carbons, and S, in a shunt-circuit, consists of fine wire in many convolutious, so as to get with a weak current magnetic force equivalent to that of S with a strong current, and to present considerable resistance. When the carbons are too near, the attractive power of S being increased, while that of S is diminished, the core F is attracted upward, separating the carbons. When, on the other hand, the carbons are too far apart, S loses force and S gains force, so that the core F is attracted downward, causing the carbons to approach. In Fig.10, showing a pendent lamp partlyin elevation and partly in section, the core F and upper carbon, E, with its socket, are balanced by the lower carbon, E, and the rods B B, which carry it, the pulleys R It, over which the balaricing cortls pass, serving as guides to the socket-tube of the upper carbon. In this lamp the connections and action of the two solenoid coilsS S are as described with reference to Fl 9. A standard lamp arranged to maintain a constant focal position of the arc produced by a continuous current is arranged as shown at Fi 11, the

racks s z of'two carbon-sockets being connected by insulated gear G D, proportioning their movements to their respective rates of consumption. The shunt-coil S may consist of two or more layers of thick insulated copper wire, furnishing the convolutions required with several layers of thin copper and Germansilver wire to provide the required resistance. An (.=lectro-n1agnet, M, in the main circuit, acting on an armature contactleveryH, serves to short-circuit the coil S in case of interruption of the lamp-circuit. Vrhen such interruption occurs the passage of current through S and H fails and the armature H t'alls,makingcon-' tact with branch 13. The current then passes outdireetly from the coarse-wire portion ot'solenoid S, thus short-circuitinp; the tine-wire portion.

*6 claim 1. A solenoid core for an electric lamp, composed of a mass of metal varying in quantity in the direction of its length, substantially as described.

2. A solenoid core for an electric lamp, consisting of a body of metal whose mass dimiir ishes toward each end, substantially as and for the purpose described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

LUDWIG PIETTE.

FRANZ KRIZIK."

Witnesscs 0. 0. Patent,

, E. G. S. MoELLna. 

